A man with a cow slurry fetish has been jailed for five years after threatening to kill a family who tried to stop him targeting their farm.

David Truscott, 43, repeatedly rolled around naked in cow slurry and developed an obsession with a farm in Redruth, Cornwall.

Exeter Crown Court heard that Truscott, formerly of Camborne, Cornwall, targeted the property over an eight-year period to indulge in his bizarre fetish.

He initially removed cow pats from the farm but his behaviour escalated, with Truscott regularly entering Woodbury House Farm to masturbate in slurry.

The court heard that Truscott decided to exact revenge on farmers Clive and Jackie Roth when they erected bollards and removed slurry from their cattle in a bid to deter him.

Truscott, who was jailed in 2005, 2009 and 2011 for his actions at the farm, repeatedly set fire to their shed, tractor, enclosures and hay - killing a calf in one blaze.

Last year, he admitted making threats to kill the Roth family and damage their property.

Today, he was handed an extended sentence of 10 years following psychiatric reports.

Judge Philip Wassall told Truscott: "When the family took steps to clear up the slurry from the cattle to prevent you from wallowing in it and took other measures to stop you getting on to their land, you began these offences.

"During a prison visit in August 2012, you made a reference to Raoul Moat and said you wouldn't mind going to prison knowing that your revenge would have been received.

"The impact on this unfortunate family, who you chanced upon and whose lives you have blighted for years, has been substantial.

"They live in fear of seeing you again."

Judge Wassall said Truscott, who has autism spectrum disorder, would spend the first five years of his prison sentence receiving hospital treatment.

He will serve an extended licence period of five years on release from prison.

The judge also imposed an extended restraining order to keep him from the farm.

Prosecuting, Eleanor Purkis said: "The defendant has a fetish in relation to animal faeces.

"His behaviour has escalated from initially removing cow pats from the farm to attending the farm and masturbating in slurry."

Truscott was jailed for three years at Truro Crown Court in 2005 after setting fire to the Roth's tractor, hay, a pen containing cattle and wooden fences.

In September 2009, he received a 16-week sentence after he stripped naked in the cattle pen, released the cattle and climbed into the slurry spreader.

On his release, Truscott returned to the farm and sat naked in cow muck. He was jailed for a further 20 weeks.

He was jailed for two years in September 2011 after police caught him naked in a field harassing the Roth family.

His latest offending was in June last year, when Truscott told support workers he wanted to "get revenge" on Mrs Roth and her 17-year-old son.

"He said 'I will buy a car with the £2,500 I have in my wardrobe and I will drive to Cornwall. I will kidnap them and I will burn them," Ms Purkis said. "'I will get great pleasure in watching them burn.'"

Truscott was described as "joyful" while describing his revenge as he played with lighters, Ms Purkis said.

In a police interview, Mrs Roth said Truscott's offences had affected the family business financially.

"She feels the place is no longer clean in relation to the sexual acts being carried out," Ms Purkis said.

"Mrs Roth broke down in tears during the interview, saying she lives in fear in her own house with her ill husband, trying to protect her children."

Truscott has four previous convictions for eight offences in relation to the Roths' farm, including arson, burglary and theft, harassment and breaching a restraining order.

Representing Truscott, Robin Smith said: "Clearly, he is a complex and troubled character."

Mr Smith said his client was released one year into his two-year sentence, on February 27 2012 and spent three and a half months in a hostel in Somerset.

"He was allowed to indulge in some of his bizarre behaviour but otherwise was compliant with all the rules and regulations," Mr Smith said.

However, Truscott was moved to a hostel in Exeter in June 2012, where he became "agitated and angry" and made threats against the Roth family the following week.

Truscott, who has a moustache and wore a blue T-shirt in the dock, remained emotionless as he was led away to begin his sentence.

Members of the Roth family, who attended court, did not wish to comment following the hearing.